PHP中的神秘代码

Question

This chunk of code was found in a script someone else wrote that I was asked to edit. It doesn't appear to be doing anything.. I'm wondering why on earth it was there and if something somewhere in the world would go terribly wrong if I remove it..

Am I missing something?

//begin mystery code - i have no idea what this chunk of code is doing..
$result = mysql_query("SHOW COLUMNS FROM ".$table."");
$i = 0;
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
$i++;
}
}
//end mystery code

$result is not referenced anywhere else..

Answer 1

It's counting the number of columns in a database table $table , and putting the value in $i

Presumably, $i is used later for something?

Answer 2

It does two things:

1. Increasing $i per row.
2. Storing each row into $row and finally false into it.

So finally it sets:

• $i to the number of rows.
• $row to false

But do not wonder about crap code much. Improve it instead:

$i   = mysql_num_rows($result);
$row = false;

Also encapsulate mysql_* calls so you can easily replace them later. You should also handle the error case if the query fails.

Answer 3

only thing it seems to do is to count number of columns in $i. If $i is not used anywhere in the script you can remove this code.

also look for $row and $result variable uses in the script if none code can be removed.